mirror of
https://github.com/cookiengineer/audacity
synced 2026-04-24 15:03:53 +02:00
Remove some old erratta, and do a major tidy up of line endings and properties on source files
This commit is contained in:
ra
@@ -1,151 +1,151 @@
|
||||
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
|
||||
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
|
||||
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
||||
<meta name="generator" content="AsciiDoc 7.1.2" />
|
||||
<link rel="stylesheet" href="./twolame.css" type="text/css" />
|
||||
<link rel="stylesheet" href="./twolame-quirks.css" type="text/css" />
|
||||
<title>The libtwolame API</title>
|
||||
</head>
|
||||
<body>
|
||||
<div id="header">
|
||||
<h1>The libtwolame API</h1>
|
||||
<span id="revision">version 0.3.11</span>
|
||||
</div>
|
||||
<div id="preamble">
|
||||
<div class="sectionbody">
|
||||
<p>This is the interface for encoding PCM audio to MPEG Audio Layer 2.</p>
|
||||
<p>It is <em>very</em> similar to the libmp3lame API.</p>
|
||||
<p>See simplefrontend/simplefrontend.c for a very simple application
|
||||
using the API.</p>
|
||||
</div>
|
||||
</div>
|
||||
<h2>Steps to encode PCM to MP2</h2>
|
||||
<div class="sectionbody">
|
||||
<ol>
|
||||
<li>
|
||||
<p>
|
||||
Grab a set of default options by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>twolame_options *encodeOptions;
|
||||
encodeOptions = twolame_init();</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Adjust those options to suit your requirements.
|
||||
See twolame.h for a full list of options. eg.
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>twolame_set_out_samplerate(encodeOptions, 32000);
|
||||
twolame_set_bitrate(encodeOptions, 160);</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Initialise twolame library with these options by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>twolame_init_params(encodeOptions);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>NOTE: The return value should be checked to see if the options were valid.
|
||||
Currently only ever returns 0</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Encode PCM audio to MP2 by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>int twolame_encode_buffer(
|
||||
twolame_options *glopts, // the set of options you're using
|
||||
const short int leftpcm[], // the left and right audio channels
|
||||
const short int rightpcm[],
|
||||
int num_samples, // the number of samples in each channel
|
||||
unsigned char *mp2buffer, // a pointer to a buffer for the MP2 audio data
|
||||
// NB User must allocate space!
|
||||
int mp2buffer_size); // The size of the mp2buffer that the user allocated
|
||||
int *mp2fill_size);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>This function returns the number of bytes written into mp2buffer by the library MPEG.
|
||||
One frame of MPEG audio will be returned for every 1152 samples of PCM audio.
|
||||
Multiple calls can be made to this function.
|
||||
It is the users responsibility to:</tt></pre>
|
||||
</div></div>
|
||||
<ul>
|
||||
<li>
|
||||
<p>
|
||||
allocate the mp2buffer
|
||||
</p>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
read the pcmaudio from somewhere with new samples always staring from
|
||||
the beginning of the buffer
|
||||
</p>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
write the mp2buffer contents to somewhere (it is overwritten with each call)
|
||||
</p>
|
||||
</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Flush the encoder by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>int twolame_encode_flush(
|
||||
twolame_options *glopts,
|
||||
unsigned char *mp2buffer,
|
||||
int mp2buffer_size);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>When encoding is finished, unless there was exactly a multiple of 1152 samples/channel
|
||||
sent to the encoder, there will be some remaining audio that is not encoded. This function
|
||||
encodes this last bit of audio by padding out with zeros until there is 1152 samples per channel
|
||||
in the PCM audio buffers and then encoding this.</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>This function returns the number of bytes written into mp2buffer by the library MPEG.</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
The user must "de-initialise" the encoder at the end by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>void twolame_close(twolame_options **glopts);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>This function must be called to free all the memory and structures
|
||||
associated with this set of encoding parameters.
|
||||
POST: glopts = NULL</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
</ol>
|
||||
</div>
|
||||
<div id="footer">
|
||||
<div id="footer-text">
|
||||
Version 0.3.11<br />
|
||||
Last updated 09-Jan-2008 11:45:17 BST
|
||||
</div>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
|
||||
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
|
||||
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
|
||||
<head>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
|
||||
<meta name="generator" content="AsciiDoc 7.1.2" />
|
||||
<link rel="stylesheet" href="./twolame.css" type="text/css" />
|
||||
<link rel="stylesheet" href="./twolame-quirks.css" type="text/css" />
|
||||
<title>The libtwolame API</title>
|
||||
</head>
|
||||
<body>
|
||||
<div id="header">
|
||||
<h1>The libtwolame API</h1>
|
||||
<span id="revision">version 0.3.11</span>
|
||||
</div>
|
||||
<div id="preamble">
|
||||
<div class="sectionbody">
|
||||
<p>This is the interface for encoding PCM audio to MPEG Audio Layer 2.</p>
|
||||
<p>It is <em>very</em> similar to the libmp3lame API.</p>
|
||||
<p>See simplefrontend/simplefrontend.c for a very simple application
|
||||
using the API.</p>
|
||||
</div>
|
||||
</div>
|
||||
<h2>Steps to encode PCM to MP2</h2>
|
||||
<div class="sectionbody">
|
||||
<ol>
|
||||
<li>
|
||||
<p>
|
||||
Grab a set of default options by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>twolame_options *encodeOptions;
|
||||
encodeOptions = twolame_init();</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Adjust those options to suit your requirements.
|
||||
See twolame.h for a full list of options. eg.
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>twolame_set_out_samplerate(encodeOptions, 32000);
|
||||
twolame_set_bitrate(encodeOptions, 160);</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Initialise twolame library with these options by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>twolame_init_params(encodeOptions);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>NOTE: The return value should be checked to see if the options were valid.
|
||||
Currently only ever returns 0</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Encode PCM audio to MP2 by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>int twolame_encode_buffer(
|
||||
twolame_options *glopts, // the set of options you're using
|
||||
const short int leftpcm[], // the left and right audio channels
|
||||
const short int rightpcm[],
|
||||
int num_samples, // the number of samples in each channel
|
||||
unsigned char *mp2buffer, // a pointer to a buffer for the MP2 audio data
|
||||
// NB User must allocate space!
|
||||
int mp2buffer_size); // The size of the mp2buffer that the user allocated
|
||||
int *mp2fill_size);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>This function returns the number of bytes written into mp2buffer by the library MPEG.
|
||||
One frame of MPEG audio will be returned for every 1152 samples of PCM audio.
|
||||
Multiple calls can be made to this function.
|
||||
It is the users responsibility to:</tt></pre>
|
||||
</div></div>
|
||||
<ul>
|
||||
<li>
|
||||
<p>
|
||||
allocate the mp2buffer
|
||||
</p>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
read the pcmaudio from somewhere with new samples always staring from
|
||||
the beginning of the buffer
|
||||
</p>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
write the mp2buffer contents to somewhere (it is overwritten with each call)
|
||||
</p>
|
||||
</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
Flush the encoder by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>int twolame_encode_flush(
|
||||
twolame_options *glopts,
|
||||
unsigned char *mp2buffer,
|
||||
int mp2buffer_size);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>When encoding is finished, unless there was exactly a multiple of 1152 samples/channel
|
||||
sent to the encoder, there will be some remaining audio that is not encoded. This function
|
||||
encodes this last bit of audio by padding out with zeros until there is 1152 samples per channel
|
||||
in the PCM audio buffers and then encoding this.</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>This function returns the number of bytes written into mp2buffer by the library MPEG.</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
<li>
|
||||
<p>
|
||||
The user must "de-initialise" the encoder at the end by calling:
|
||||
</p>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>void twolame_close(twolame_options **glopts);</tt></pre>
|
||||
</div></div>
|
||||
<div class="literalblock">
|
||||
<div class="content">
|
||||
<pre><tt>This function must be called to free all the memory and structures
|
||||
associated with this set of encoding parameters.
|
||||
POST: glopts = NULL</tt></pre>
|
||||
</div></div>
|
||||
</li>
|
||||
</ol>
|
||||
</div>
|
||||
<div id="footer">
|
||||
<div id="footer-text">
|
||||
Version 0.3.11<br />
|
||||
Last updated 09-Jan-2008 11:45:17 BST
|
||||
</div>
|
||||
</div>
|
||||
</body>
|
||||
</html>
|
||||
|
||||
Reference in New Issue
Block a user